Briggs Vanguard 14/16HP & 18/20HP Engine Upgrades and Identification

[thinhorn]

I just got a 2015 580 6x6 for a second machine.Ive put 30 hrs on it since picking up mid November.Ive changed the oil twice my question is its smells like it pretty rich I'm wondering if removing those exhaust restrictors will lean it out a bit or can a guy rejet these engines .Power seems good ,pretty happy with this little machine it handles like a sports care compared to my avenger.tks for any info Robin

[RAMHVAC]

Jpsswift1,

Great post I was pretty excited to gain the cheap 2 extra HP. I have the 14 hp vtwin. I pulled the exhaust manifold and did not see restrictors? How obvious are the sleeves? Could I be missing them? FYI my motor is a 2013.

Thanks,

[Rck90]

Hey, Hiballer, did you pull out those restrictors?

[liflod]

Vanguard governor modification.[/B]
Here's how I bypass my governor on my machines. The governor is used until the throttle is about 1/2 to 3/4, then the govenor is bypassed.

Thread a piece of throttle cable through the governor spring using the same holes as the spring uses.
https://photos.app.goo.gl/I3O9axy4yB8pxBLX2


Install cable stop on open end of cable.


Start the engine and let the governor settle in. Move the throttle stop down the cable leaving about 1/4 inch or so of slack. This may need moved depending on your set up.

So now the throttle works against the governor spring until the spring stretches to the length of the cable. It is nice to have the governor when technical riding and bypassing it on the open smooth trails. Works great to get the extra RPMS out of your machine when needed.

[Nubs]

Very Nice

Looks like there is enough room that a fella could drill a hole in the governor arm and run the cable out the back side also.

Good post...

[liflod]

If you run it out the back, you need to remove the air cleaner to adjust it. I'm not sure how a bolt would work, but it may be worth a try.

[Regulator]

I posted a 20hp carb and intake in the for sale section if anyone one wants some quick power!

[Norbert77]

OK everyone, I'm going to try and help anyone out that might be wondering about upgrading or identifying the 14HP/16HP or 18/20HP Briggs Vanguard they have. This has been discussed before, but I'm going to lay out all the details for everyone.

First off, if you have a 14HP Briggs Vanguard in your Max or Argo and want 2HP more, inexpensively and easily, this is for you. This is also a good way to tell if you have a 14HP or 16HP Vanguard (I know, it usually says the HP on the air cleaner decal or you can trace it by the engine ID tag). The 14HP and 16HP are both 480cc engines and are pretty much the same with 2 minor differences. First, the 16HP has a slightly larger carburetor venturi. Pick up a 16HP carburetor (off ebay or Craigslist) for your 14HP Vanguard and bolt it right on. Next, remove the exhaust manifold and look in the exhaust ports. If you see one of these little power robbing b@stards in each of the ports, then you have a 14HP engine. All you have to do is simply remove these pieces of junk with some pliers and you're set. Now with the new carb and no restriction in the exhaust, you have a 16HP engine.

The same goes for the 18HP and 20HP Vanguards. They share the same displacement as each other, 570cc. The 18HP Vanguards have those darn exhaust restrictors in the exhaust ports of the heads and a smaller single barrel carb. The 20HP Vanguards don't have the restrictor rings and they have a 2 barrel carb, but you'll have to get the carb, intake manifold, carb spacer, and tin air cleaner bottom if you want to upgrade your 18HP to a 20HP engine.

Here's a picture of one of those power robbing restrictor rings found on the 14HP and 18HP Vanguards. After you remove them you'll want to turn the plastic tab on the carb for the fuel mixture to richen it up so you compensate for the freer flowing exhaust you now have.

I was looking at this little ring - tube thingie, to me it looks like a locating pin to keep the exhaust in place while it's being bolted up. The head seems larger where it goes, so it wouldn't add restriction. Are there pics of the exhaust ports compared?

[wjs0311]

I assume the answer is yes but we all know what happens when you assume... Will 14 hp heads fit on a 18 and will they give better compression than stock?

[jpswift1]

I assume the answer is yes but we all know what happens when you assume... Will 14 hp heads fit on a 18 and will they give better compression than stock?

Good question, I don't think they will but I can't say for sure. I think Performance V-Twins - Monroe, NC sells a copper head gasket kit to give you a slight bump in compression.